Degree of Verticillium Wilt Infection and the Relative Damage in Fiber Quality Parameters
Mar 27, 2019
Verticillium wilt is a major problem in many cotton producing countries. In addition to causing big losses in yield, deterioration in fiber quality affects the commercial value of cotton. This study was undertaken to determine the damage caused in fiber quality characters by various degrees of Verticillium wilt infection. Four commercial cotton cultivars (G. hirsutum), varying in earliness and vulnerability to the pathogen, were used. Based on visual symptoms the degree (level) of infection ranged from 0 to 4. Eleven representative plants from each infection level and from each cultivar under study, were labelled and their product was bulked, ginned and evaluated for most fiber properties. Fiber length parameters were the least affected, except for the short fiber content (SFC) which was nearly doubled in the highest level. Micronaire deterioration was highly depended on the cultivar, while maturity was significantly decreased from 0 to 4 degree in all cultivars. Immature fiber content (IFC) increased and fineness decreased mainly in the highest two degrees. Fiber neps were dramatically increased in the highest degree but nevertheless cultivar plays an important role too. The same applies for trash and seed coat neps. The general conclusion is that fiber damage in the wilted plants was analogous to the severity of infection. Thus fibers from the higher degree are unsuitable as spinning raw material because they are below spinnable limits in all cultivars. In the lower degrees, fiber damage depends on the cultivar.